Essentials #70-058 - APlus Training

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Oct 26, 2013 (3 years and 9 months ago)

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Exam #70
-
058


About the Networking Essentials Exam


The Networking Essentials exam requires you to answer 58 questions over a 75
-
minute period. The passmark
for the exam is 793 / 1000. Networking Essentials counts as one of the four 'core' exams require
d for MCSE,
it covers quite a wide range of topics and there's a lot to learn so let's get started...


The exam consists of four sections covering the following objectives. This reference guide will deal with each
of the objectives in the turn: Skip to th
e useful stuff if you know this already


i) Standards and Terminology



Define common networking terms for LAN's and WAN's



Compare a file and print server with an application server



Compare user
-
level security with access permissions assigned to a shared d
irectory on a server



Compare a client/server network with a peer
-
to
-
peer network



Compare the implications of using connection
-
oriented communication with connectionless communication



Distinguish whether SLIP or PPP is used as the communication protocol
for various situations



Define the communications devices that communicate at each level of the OSI model



Describe the characteristics and purpose of the media used in IEEE 802.3 and IEEE 802.5 standards



Explain the purpose of NDIS and Novell ODI network

standards


ii) Planning



Select the appropriate media for various situations. Media choices include:



twisted
-
pair cable, coaxial cable, fibre
-
optic cable and wireless communication



Select the appropriate topology for various Ethernet and Token Ring netw
orks



Select the appropriate network and transport protocols for various Ethernet and Token Ring networks.
Protocols include:



DLC, AppleTalk, IPX, TCP/IP, NFS and SMB



Select the appropriate connectivity devices for various Ethernet and Toke Ring networks.

Connectivity
devices include:



repeaters, bridges, routers, brouters and gateways



List the characteristics, requirements and appropriate situations for WAN connection services. WAN
connection services include:



X.25, ISDN, Frame Relay and ATM


iii) Implem
entation



Choose an administrative plan to meet specific needs including performance management, account
management and security



Choose a disaster recovery plan for various situations



Given the manufacturers documentation for the network adapter, install
, configure and resolve hardware
confilcts for multiple network adapters in an Ethernet or Token Ring network



Implement a NetBIOS naming scheme for all computers on a given network



Select the appropriate hardware and software tools to monitor trends in t
he network


iv) Troubleshooting

Identify common errors associated with components required for communication



Diagnose and resolve common connectivity problems with cards, cables and related hardware



Resolve broadcast storms



Identify and resolve networ
k performance problems



Define common networking terms for LAN's and WAN's

Networks, LAN's and WAN's


A network can be defined as "a group of interconnected computers that share information and resources". In
it's simplest form, a network can consist of

two computers communicating over a single cable.


The term LAN stands for
Local Area Network
. A LAN is a group of computers networked within an office,
building or campus.


A WAN or
Wide Area Network

usually consists of computers in separate geographica
l areas interconnected by
means of leased lines, telephone lines or microwave, radio and satellite links. A good example of a WAN could
be a company with offices in two different cities whose LAN's share information over an ISDN line.


Network Topology


You will come across the term Network Topology many times in the Networking Essentials exam. Network
Topology refers to the physical layout of a network. These are the topologies you will need to be familiar with.
They will be described in full under the o
bjective "Select the appropriate topology for various Ethernet and
Token Ring networks":







Bus Topology
: Single cable connecting all computers on the network in a line

Star Topology:

All computers on the network are connected directly to a ce
ntral hub

Ring Topology:

Each computer is connected to the next in a ring with no end to the network

Mesh Topology:

Each computer is connected to every other computer on the network forming a mesh


Protocols


In order to communicate with each other compu
ters must follow a common set of communication rules. These
rules are referred to as protocols. There are many different network protocols currently in use but the ones you
will need to be familiar with for the exam include; TCP/IP, IPX/SPX, NetBEUI, Apple
Talk and DLC. If you don't
know what the acronyms mean, don't worry, protocols will be covered in greater detail later under the objective
"Select the appropriate network and transport protocols for various Ethernet and Token Ring networks".


Compare a fil
e and print server with an application server



File Servers


A File Server provides file
-
sharing services to other computers on the network. Since a file server's main task
is to provide storage for a large number of files, file servers commonly require l
arge amounts of memory and
high capacity disks with some form of fault tolerance usually
RAID (Redundant Array of Inexpensive Disks)



Print Servers


Print Servers provide access to shared printers on the network, making a small number of printers availabl
e to
a large number of users. Since a print server will receive print jobs from computers on the network much faster
than the printer can print them a print server will usually use a process called spooling. A spooler will write the
print jobs received by
the print server to the hard disk and will send the jobs to the printer when it becomes
available.


Application Servers


An application server runs all or part of an application on behalf of a client computer and can then send any
resulting data to the cl
ient for further processing. The most common example of an application server is a SQL
database server. A SQL server receives a request for information from a client computer, locates the
information in the database, processes it and returns the results to

the client.


Compare user
-
level security with access permissions assigned to a shared directory on a server


The two basic security models covered by the Networking Essentials exam are
share
-
level security

otherwise known as
password
-
protected shares

an
d
user
-
level security

often referred to as
access
permissions
. Before we continue, you need to be aware of the term
resource
. A resource can be any device
(e.g. a printer) or information (e.g. data files) on the network. When a resource is available for us
e on the
network we can call it a
shared resource
.


Share
-
Level Security


In the share
-
level security model each shared resource on the network is assigned a password. In order to
gain access to the resource a user must enter the correct password for that

resource. A 10 user Windows 95
peer
-
to
-
peer network is a good example of a network that implements share
-
level security.


User
-
Level Security


Some network operating systems such as Windows NT Server use a more advanced and flexible security
model called

user
-
level security. Rights and permissions to shared resources on the network are assigned on
a user
-
by
-
user basis. To gain access to shared resources a user must first
log on

to the network by supplying
a valid username and password. When a user attempt
s to access a shared resource the server will validate
the user and grant access to the resource based on the permissions associated with the user for that
resource. A 50 user NT Server based network with Windows 95 and NT Workstation clients with users
ma
naged centrally on the server is a good example of a network using user
-
level security.


Compare a client/server network with a peer
-
to
-
peer network



Peer
-
to
-
Peer Network


In a peer
-
to
-
peer network all the computers on the network operate as equals (peer
s) that both share and use
resources. Essentially, each computer is both a client and a server. Every computer is responsible for
managing it's own shared resources. Peer
-
to
-
peer networks are usually quite small and generally consist of 10
or fewer compute
rs. Peer
-
to
-
peer networks usually implement share
-
level security.

Windows 3.11 for Workgroups, Windows 95/98 and Windows NT Workstation can operate in a peer
-
to
-
peer
network.



Advantages include: low cost, easy to set up & no need for centralized administ
ration



Disadvantages include: poor security, limited growth & requires more knowledgeable users


Client/Server Network


In a server based network large numbers of client computers request and use resources from a smaller
number of higher performance serve
r computers. The server
-
based network is usually managed centrally by a
network administrator. Server based networks implement user
-
level security.

Windows NT Server is used to build a server
-
based network. Windows 95/98 and NT Workstation can act as
clie
nts in a server based network. NOTE: NT Server supports an unlimited number of connections but NT
Workstation can only support a maximum of 10 concurrent connections.



Advantages include: Strong security, centralized management of large number of users & p
otential for
growth



Disadvantages include: Expensive to set up, more difficult to set up & usually requires a dedicated network
administrator


Compare using connection
-
oriented communication with connectionless communication



Communication between compu
ters on a network can be handled using two different methods:


Connection Oriented Communication


A logical pathway (connection) is formed between the source computer and the destination computer. The
node (chain of links along the pathway between source
and destination) forwarding packets along this
pathway provide error correction and flow control to ensure that packets are delivered in sequence & error
free.



Advantages include: guaranteed delivery of packets



Disadvantages include: slower



Connectionl
ess Communication


No logical pathway is formed. With connectionless communication the source computer assumes packets sent
will reach their destination error
-
free. Connectionless communication is faster than connection oriented
communication because nodes

between the source and destination only forward packets but do not perform
any error correction or flow control.



Advantages include: faster



Disadvantages include: no guaranteed deliver of packets


Distinguish whether SLIP or PPP is used as the communica
tion protocol for various situations



Serial Line Internet Protocol (SLIP) and Point
-
to
-
Point Protocol (PPP) are primarily used for dial
-
up access to
networks. An objective of the Networking Essentials exam is that you understand the differences between t
he
two and know in what situation to use them.


Serial Line Internet Protocol (SLIP)


SLIP was implemented in 1984 and is the older of the two protocols. It is a simple protocol that functions at the
Physical layer of the OSI model. SLIP only supports the

TCP/IP protocol and does not support automatically
assigned IP addresses. Therefore, a computer using SLIP to connect to a network must have a valid IP
address for that network.


Point
-
to
-
Point Protocol (PPP)


PPP is a more recent and more enhanced proto
col than SLIP. It functions at the Physical and the Data Link
layer of the OSI model. PPP supports dynamic IP addressing (via DHCP), offers support for multiple protocols
(IPX/SPX, NetBEUI, TCP/IP, AppleTalk) and provides a certain amount of error checking
. PPP is currently the
most popular dial
-
up serial line protocol.


Define the communications devices that communicate at each level of the OSI model


A thorough understanding of the OSI model is essential for passing the Networking Essentials exam. Know
and understand the purpose of each layer. Take your time to learn it and be familiar with the devices and
protocols that operate at each of the layers.

The acronym OSI stands for Open Systems Interconnection. The OSI model was introduced in 1984 by the
In
ternational Standards Organization. It's goal was to define a standard for the flow of information across
networks. The seven layers of the OSI model are described below:





Usually, the questions on the Networking Essentials exam relating to the OSI mo
del provide you with a basic
diagram (no descriptions) of the model. However, you should be able to recite the names and the order of
each of the layers (and understand the purpose of each of the layers) before you are ready to take the exam.
The most comm
on method for memorizing the order of the OSI model is from the top down:

All People Seem To Need Data Processing


IEEE 802.5 standards


In 1980, the Institute of Electrical and Electronic Engineers started to 802 project which sets out to define a
serie
s of standards relating to the physical cabling and data transmission for LAN's and WAN's. The IEEE 802
standards are currently organized into 12 categories. These categories are listed below:


802.1

802.2

802.3

802.4

802.5

802.6

802.7

802.8

802.9

802.10

8
02.11

802.12

Internetworking

Logical Link Control

Carrier Sense Multiple Access with Collision Detection (CSMA/CD)

Token Bus LAN

Token Ring LAN

Metropolitan Area Network (MAN)

Broadband Technical Advisory Group

Fibre Optic Technical Advisory Group

Integrat
ed Voice/Data Networks

Network Security

Wireless Networks

Demand Priority Access LAN (100BaseVG
-

AnyLAN)